I know you are no newcomer when it comes to stuff on the roof, but an old trick that is helpful in saving masts and all during those downdrafts gusts and rough weather that is coming (I had one brief 90 mph gust last year) is to put as big of an outside diameter pipe that will fit inside the mounting pipe. Even if it isn't a tight fit, the outer one will flex against it and then gain quite a bit of strength over what just the outer pipe alone would offer.
Sounds like your yagi did what my 2 meter vertical yagi did up at almost 100' a few years ago. I went out the next morning after a pretty good storm overnight and looked up. HF beam and the OTA TV stuff was still oriented where the rotor left it, but the yagi was now 60 degrees anti clockwise with the rest. I don't use it much and don't have the gumption at this time of my life to even try to get it straightened out or look for an Elmer with nads enough to climb up there to re-orient it, so there it stays. I just tell my wife it evens out the wind load!
You said that the Weather Company owns WU and the Wx Channel, but they also say they are an IBM company. I hope a loosely held one, since I have no respect for the Wx Channel (sorry, its just me) and the WU has gotten plenty of bad ink from folks I respect lately, so I try not to hold that against IBM.
One of the guys who used to be a meteorologist for WCCO, Channel 4 out of the Twin Cities (which we watch for our weather since that is where most of it comes from and they have big bucks to buy the toys and services and pay for good on the air talking heads which also seem to think, especially all of their chiefs over the years) and Dr. Walt Lyons who was a respected researcher in lightning for many years went on to work with the Vaisala network, if I recall. We met him by accident down in AZ at the same motel we were staying at. Very personable. A real gentleman and would have loved to discuss even an evening's worth of lightning topics with him if it would have been possible. I think I've been blessed to have as professors or know incidentally so many people who've done some original research.
Keep us posted on your antenna mounting travails until you are set up.
I'm going out in bright (but cold) sunshine to get one of the tripod mounts on my shed converted over so when the package does arrive I'll be able to proceed with getting it mounted and on the air. Storm season is coming.